Wideband mechanical energy harvester based on piezoelectric longitudinal mode

This paper presents how an adjustable electrical load can be used to achieve a wideband mechanical vibration energy harvester based on piezoelectric material. We discuss within this paper the design optimization of the developed structure in terms of coupling mode and cantilever shape. The developed device is based on longitudinal piezoelectric mode; it features two principal modes, 208 Hz at short circuit condition and 294 Hz at open condition. The adjustable electrical load coupled with the piezoelectric material will allow a controllable shift of the resonant frequency between these two principal modes.